Note
Go to the end to download the full example code.
Ship drift
from datetime import datetime
from opendrift.models.shipdrift import ShipDrift
o = ShipDrift(loglevel=20)
o.add_readers_from_list([
'https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml',
'https://thredds.met.no/thredds/dodsC/mepslatest/meps_lagged_6_h_latest_2_5km_latest.nc',
'https://thredds.met.no/thredds/dodsC/cmems/mywavewam3km/dataset-wam-arctic-1hr3km-be.ncml'
])
14:12:34 INFO opendrift:569: OpenDriftSimulation initialised (version 1.14.3 / v1.14.3-25-gcd89af5)
Seed ship elements at defined position and time Note: beam/length ratio is larger than allowed, but is then clipped internally
o.seed_elements(lon=5.0, lat=63.0, radius=1000, number=1000,
time=datetime.now(),
length=80.0, beam=20.0, height=9.0, draft=4.0)
14:12:34 WARNING opendrift.models.shipdrift:181: Ratio of beam to length should be in range 0.12 to 0.18, given range is 0.25-0.25. Using border value.
14:12:34 INFO opendrift.models.basemodel.environment:206: Adding a global landmask from GSHHG
14:12:38 INFO opendrift.models.basemodel.environment:229: Fallback values will be used for the following variables which have no readers:
14:12:38 INFO opendrift.models.basemodel.environment:232: sea_surface_wave_stokes_drift_x_velocity: 0.000000
14:12:38 INFO opendrift.models.basemodel.environment:232: sea_surface_wave_stokes_drift_y_velocity: 0.000000
14:12:38 INFO opendrift.models.basemodel.environment:232: sea_surface_wave_significant_height: 0.000000
14:12:38 INFO opendrift.models.basemodel.environment:232: sea_surface_wave_mean_period_from_variance_spectral_density_second_frequency_moment: 0.000000
Running model
o.run(steps=24, stop_on_error=True)
14:12:38 INFO opendrift:1790: Storing previous values of element property lon because of condition (('general:coastline_action', 'in', ['stranding', 'previous']), 'or', ('general:seafloor_action', 'in', ['previous']))
14:12:38 INFO opendrift:1790: Storing previous values of element property lat because of condition (('general:coastline_action', 'in', ['stranding', 'previous']), 'or', ('general:seafloor_action', 'in', ['previous']))
14:12:38 INFO opendrift:945: Using existing reader for land_binary_mask to move elements to ocean
14:12:38 INFO opendrift:975: All points are in ocean
14:12:38 INFO opendrift:2086: 2025-10-03 14:12:34.790869 - step 1 of 24 - 1000 active elements (0 deactivated)
14:12:38 INFO opendrift.readers:63: Opening file with xr.open_dataset
14:12:40 INFO opendrift.readers.reader_netCDF_CF_generic:332: Detected dimensions: {'x': 'x', 'y': 'y', 'time': 'time'}
14:12:40 INFO opendrift.readers:63: Opening file with xr.open_dataset
14:12:41 INFO opendrift.readers.reader_netCDF_CF_generic:332: Detected dimensions: {'time': 'time', 'x': 'x', 'y': 'y'}
14:12:41 INFO opendrift.readers:63: Opening file with xr.open_dataset
14:12:44 INFO opendrift.readers.reader_netCDF_CF_generic:332: Detected dimensions: {'y': 'rlat', 'x': 'rlon', 'time': 'time'}
14:12:45 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:12:45 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:12:45 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:12:45 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:12:47 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:12:47 INFO opendrift:2086: 2025-10-03 15:12:34.790869 - step 2 of 24 - 1000 active elements (0 deactivated)
14:12:48 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:12:48 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:12:48 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:12:49 INFO opendrift:2086: 2025-10-03 16:12:34.790869 - step 3 of 24 - 1000 active elements (0 deactivated)
14:12:50 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:12:50 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:12:50 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:12:50 INFO opendrift:2086: 2025-10-03 17:12:34.790869 - step 4 of 24 - 1000 active elements (0 deactivated)
14:12:51 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:12:51 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:12:52 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:12:52 INFO opendrift:2086: 2025-10-03 18:12:34.790869 - step 5 of 24 - 1000 active elements (0 deactivated)
14:12:53 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:12:53 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:12:54 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:12:54 INFO opendrift:2086: 2025-10-03 19:12:34.790869 - step 6 of 24 - 1000 active elements (0 deactivated)
14:12:55 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:12:55 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:12:56 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:12:56 INFO opendrift:2086: 2025-10-03 20:12:34.790869 - step 7 of 24 - 1000 active elements (0 deactivated)
14:12:57 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:12:57 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:12:58 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:12:58 INFO opendrift:2086: 2025-10-03 21:12:34.790869 - step 8 of 24 - 1000 active elements (0 deactivated)
14:12:59 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:12:59 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:12:59 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:12:59 INFO opendrift:2086: 2025-10-03 22:12:34.790869 - step 9 of 24 - 1000 active elements (0 deactivated)
14:13:01 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:01 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:01 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:13:01 INFO opendrift:2086: 2025-10-03 23:12:34.790869 - step 10 of 24 - 1000 active elements (0 deactivated)
14:13:04 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:04 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:05 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:13:05 INFO opendrift:2086: 2025-10-04 00:12:34.790869 - step 11 of 24 - 1000 active elements (0 deactivated)
14:13:06 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:06 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:07 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:13:07 INFO opendrift:2086: 2025-10-04 01:12:34.790869 - step 12 of 24 - 1000 active elements (0 deactivated)
14:13:08 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:08 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:09 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:13:09 INFO opendrift:2086: 2025-10-04 02:12:34.790869 - step 13 of 24 - 1000 active elements (0 deactivated)
14:13:10 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:10 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:11 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:13:11 INFO opendrift:2086: 2025-10-04 03:12:34.790869 - step 14 of 24 - 1000 active elements (0 deactivated)
14:13:12 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:12 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:13 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:13:13 INFO opendrift:2086: 2025-10-04 04:12:34.790869 - step 15 of 24 - 1000 active elements (0 deactivated)
14:13:14 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:14 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:15 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:13:15 INFO opendrift:2086: 2025-10-04 05:12:34.790869 - step 16 of 24 - 1000 active elements (0 deactivated)
14:13:16 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:16 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:17 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:13:17 INFO opendrift:2086: 2025-10-04 06:12:34.790869 - step 17 of 24 - 1000 active elements (0 deactivated)
14:13:18 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:18 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:19 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:13:19 INFO opendrift:2086: 2025-10-04 07:12:34.790869 - step 18 of 24 - 1000 active elements (0 deactivated)
14:13:21 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:21 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:21 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:13:21 INFO opendrift:2086: 2025-10-04 08:12:34.790869 - step 19 of 24 - 1000 active elements (0 deactivated)
14:13:23 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:23 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:24 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:13:24 INFO opendrift:2086: 2025-10-04 09:12:34.790869 - step 20 of 24 - 1000 active elements (0 deactivated)
14:13:25 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:25 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:26 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:13:26 INFO opendrift:2086: 2025-10-04 10:12:34.790869 - step 21 of 24 - 1000 active elements (0 deactivated)
14:13:27 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:27 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:28 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:13:28 INFO opendrift:2086: 2025-10-04 11:12:34.790869 - step 22 of 24 - 1000 active elements (0 deactivated)
14:13:29 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:29 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:30 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:13:30 INFO opendrift:2086: 2025-10-04 12:12:34.790869 - step 23 of 24 - 1000 active elements (0 deactivated)
14:13:32 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:32 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:33 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
14:13:33 INFO opendrift:2086: 2025-10-04 13:12:34.790869 - step 24 of 24 - 1000 active elements (0 deactivated)
14:13:35 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:35 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
14:13:36 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
Print and plot results
print(o)
o.plot(linecolor='orientation')
#o.animation(color='orientation', markersize=20, filename="orientation.gif", legend=['left','right'],colorbar=False,cmap='bwr')
o.animation(color='orientation', legend=['left','right'], markersize=20, colorbar=False, cmap='bwr')
===========================
--------------------
Reader performance:
--------------------
global_landmask
0:00:00.0 total
0:00:00.0 preparing
0:00:00.0 reading
0:00:00.0 masking
--------------------
https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml
0:00:15.3 total
0:00:00.0 preparing
0:00:15.2 reading
0:00:00.0 interpolation
0:00:00.0 interpolation_time
0:00:00.0 rotating vectors
0:00:00.0 masking
--------------------
https://thredds.met.no/thredds/dodsC/mepslatest/meps_lagged_6_h_latest_2_5km_latest.nc
0:00:17.9 total
0:00:00.0 preparing
0:00:17.8 reading
0:00:00.3 interpolation
0:00:00.0 interpolation_time
0:00:00.0 rotating vectors
0:00:00.0 masking
--------------------
https://thredds.met.no/thredds/dodsC/cmems/mywavewam3km/dataset-wam-arctic-1hr3km-be.ncml
0:00:18.0 total
0:00:00.0 preparing
0:00:17.9 reading
0:00:00.0 interpolation
0:00:00.0 interpolation_time
0:00:00.0 rotating vectors
0:00:00.0 masking
--------------------
Performance:
1:02.0 total time
3.9 configuration
0.0 preparing main loop
0.0 moving elements to ocean
58.0 main loop
0.5 updating elements
0.0 cleaning up
--------------------
===========================
Model: ShipDrift (OpenDrift version 1.14.3)
1000 active ShipObject particles (0 deactivated, 0 scheduled)
-------------------
Environment variables:
-----
land_binary_mask
1) global_landmask
-----
x_sea_water_velocity
y_sea_water_velocity
1) https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml
2) https://thredds.met.no/thredds/dodsC/cmems/mywavewam3km/dataset-wam-arctic-1hr3km-be.ncml
-----
x_wind
y_wind
1) https://thredds.met.no/thredds/dodsC/mepslatest/meps_lagged_6_h_latest_2_5km_latest.nc
-----
sea_surface_wave_mean_period_from_variance_spectral_density_second_frequency_moment
sea_surface_wave_significant_height
sea_surface_wave_stokes_drift_x_velocity
sea_surface_wave_stokes_drift_y_velocity
1) https://thredds.met.no/thredds/dodsC/cmems/mywavewam3km/dataset-wam-arctic-1hr3km-be.ncml
Discarded readers:
Time:
Start: 2025-10-03 14:12:34.790869 UTC
Present: 2025-10-04 14:12:34.790869 UTC
Calculation steps: 24 * 1:00:00 - total time: 1 day, 0:00:00
Output steps: 25 * 1:00:00
===========================
14:13:50 INFO opendrift:4613: Saving animation to /root/project/docs/source/gallery/animations/example_shipdrift_0.gif...
14:14:06 INFO opendrift:3054: Time to make animation: 0:00:16.713505
Total running time of the script: (1 minutes 38.510 seconds)